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Explicit simulation of cumulus ensembles with the GATE phase III data: Budgets of a composite easterly wave
Author(s) -
Xu KuanMan,
Randall David A.
Publication year - 2001
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49712757506
Subject(s) - tropical wave , mesoscale meteorology , convection , diabatic , precipitation , climatology , geology , atmospheric sciences , equatorial waves , meteorology , physics , adiabatic process , geodesy , latitude , equator , thermodynamics
The mass, heat and moisture budgets of a composite easterly wave over the eastern tropical Atlantic are analysed from simulations of a convection‐resolving model (CRM). The large‐scale data from the GARP (Global Atmospheric Research Program) Atlantic Tropical Experiment (GATE) phase III are used to drive the CRM simulations. The simulated, composite easterly wave is reasonably comparable with the observed, except for the lack of shallow convection embedded in the simulated easterly waves. The mesoscale stratiform precipitation processes are found to be an inseparable component of cumulus convection embedded in the easterly waves. Their main differences from convective processes are twofold: (1) the distinct vertical structures of the budget components due to mesoscale updraughts and downdraughts, and (2) the phase lags relative to the convective processes in the temporal evolution of the easterly waves. Thus, theoretical studies should include both convective and mesoscale stratiform precipitation processes in order to further understanding of diabatic processes in the dynamics of the easterly waves and possibly other waves in the tropics. In addition, the budget analysis presented in this study also provides some details for improving parametrizations of cumulus convection.